Re: Suggestions for a sub $500 optics for AR carbine?
It all depends on your ultimate application.
If you don't need illumination, weaver makes a very fine 1-3x scope that is an excellent optic for general daylight use.
Falcon Optics makes a dandy 1.5-5x optics, very good for hunting and range use.
You can always check out any of the shotgun and muzzleloader scopes made by various manufactuers. They usually have a reticle that is quite fast to pick up and also capable of very good accuracy, plus they have very forgiving eye relief.
There is the aforementioned Burris Tac-30 and the Vortex available.
Don't discount a good red dot sight for those shots out to 150 yards either. They are VERY fast to acquire and give good accuracy out to that range, though it is "battle" accuracy and not target accuracy.
Many folks are happy with their Millet DMS scopes, though the quality can be spotty. I believe primary arms has their own version of the same scope.